Higher Order Function

A higher order function is a function that takes one or more functions as argument and returns a function as its result. With higher order function, we can use existing functionalities of Swift to achieve more with less effort.

Swift has multiple higher order functions like:

1. Map
2. Compact Map
3. Map Values
4. Flat map
5. Filter
6. Reduce
7. For Each
8. Remove All
9. Sorted
10. Contains
11. Split